Positioning control system

Abstract

A positioning control system which has a servo system provided with a position feedback system for detected positional information and a velocity feedback system for detected velocity information of a motor and in which the motor is driven by the servo system in accordance with commanded positional information to position a movable machine part of a numerical-controlled machine. The disparity between the detected velocity of the movable machine part and the detected motor velocity is fed back to the control input side of the motor, thereby suppressing vibration of the movable machine part at the moment of completion of the positioning operation.

What is claimed is: 
     
       1. A control system for positioning a movable machine part that is connected to a motor in a numerically controlled machine, by feedback within said system of selected positional information of said motor or said machine part, and of information of the velocity of the motor, said control system receiving commanded positional information to operate said system to drive said motor to control the machine part, said control system comprising means for detecting said velocity information of said motor,   means for providing said selected positional information,   means for providing information corresponding to the velocity of the machine part, and   first difference means for outputting the difference between said velocity information of the machine part and said detected motor velocity information for said feedback.   
     
     
       2. The system of claim 1 comprising said means for detecting said velocity information of said motor comprising a velocity detector coupled with the motor, and   said means for providing said information corresponding to said velocity information of the machine part comprising a velocity detector coupled to said machine part.   
     
     
       3. The system of claim 1, wherein said selected positional information is of the position of said machine part, said system comprising said means for providing said information corresponding to said machine part velocity comprising means for detecting the positional information of said machine part and for converting said detected positional information of said machine part into said velocity information of said machine part, and   said means for detecting said positional information of said machine part comprising a position detector coupled with the machine part.   
     
     
       4. The system of claim 2, comprising a position detector connected to said velocity detector of said motor for providing the positional information of the motor as said selected positional information. 
     
     
       5. The system of claim 4 comprising second difference means for outputting the difference between said commanded position information and said positional information of said motor,   third difference means for outputting the difference between a signal corresponding to the output of the second difference means and said velocity information of said motor,   fourth difference means for outputting the difference between the output of the third difference means and a signal corresponding to the output of said first difference means, and   means for driving said motor with the output of said fourth difference means.   
     
     
       6. The system of claim 2, said predetermined positional information representing the position of the machine part, said system comprising a position detector coupled to said machine part to provide said machine part positional information. 
     
     
       7. The system of claim 6 comprising second difference means for outputting the difference between said commanded position information and said positional information of the machine part,   third difference means for outputting the difference between a signal corresponding to the output of said second difference means and the velocity information of said motor,   fourth difference means for outputting the difference of the output of said third difference means and a signal corresponding to the output of said first difference means, and   means for driving the motor with the output of the fourth difference means.   
     
     
       8. The system of claim 3 comprising second difference means for outputting the difference between the commanded positional information and the position information of the machine part,   third difference means for outputting the difference between a signal corresponding to the output of the second difference means and the velocity information of the motor,   fourth difference means for outputting the difference between the output of the third difference means and a signal corresponding to the output of said first difference means, and   means for driving the motor with the output of the fourth difference means.   
     
     
       9. The system of claim 5, 7, or 8 comprising a first amplifier (AMP 1) connected between said second and third difference means, and   a second amplifier (AMP 3) connected between said first and fourth difference means.